Starch is the most common carbohydrate in the human body. Starch is made out of two polysaccharides: amylopectin (water-soluble, highly branched polymer of glucose) and amylose (insoluble in water and is more resistant to digestion) . Some cultivated plants have pure amylopectin starch without amylose, known as waxy starches. The most popular among them is waxy maize starch (or waxy corn starch).
The firms that produce and sell waxy maize claim that it is a very fast carbohydrate due to its high amylopection content. They even claim that it is more quickly absorbed than dextrose or maltodextrin which should result in much greater glycogen storage.
There are very few studies performed on waxy maize starch. However, there is one relevant study conducted on trained athletes and with waxy maize supplemented pre-workout. This study compared the physiological responses and performance following the ingestion of a waxy starch (W), resistant starch (R), glucose (G) and placebo (P) ingested pre-workout. In contrast to what is marketed, results show both blood glucose and insulin levels were similar for waxy starch and slow starch but were 3 times higher with glucose. All carbohydrates provided an ergogenic benefit without statistically significant differences.
Amanda L. Sands et al.  investigated the glycemic response of waxy maize starch compared to a maltodextrin-sucrose mixture (MS), and white bread. Compared to MS, waxy maize had lower 4-hour glucose and insulin response. In fact, it was similar to that of a white bread.
One study showed no difference in 24-hour glycogen resynthesis between waxy maize, dextrose, maltodextrin or slow starch . So, waxy maize starch is at best similar to other fast acting carbohydrates. Considering waxy maize is much more expensive than other fast carbohydrates you should probably save your money and get more out of it if you go with maltodextrin or dextrose for your post-workout glycogen refuel.
- http://www.gmo-compass.org/eng/glossary/ Retrieved 15. March 2013
- Goodpaster, B. H., et al. “The effects of pre-exercise starch ingestion on endurance performance.” International journal of sports medicine 17.05 (2007): 366-372.
- Sands, Amanda L., et al. “Consumption of the slow-digesting waxy maize starch leads to blunted plasma glucose and insulin response but does not influence energy expenditure or appetite in humans.” Nutrition Research 29.6 (2009): 383-390.
Jozsi, A. C., et al. “The influence of starch structure on glycogen resynthesis and subsequent cycling performance.” International journal of sports medicine 17.05 (2007): 373-378.